Pacpus tutorials

Foreword

Before reading these tutorials, please have a look at the GettingStarted page in order to install the framework.

Don't forget to check that the environment variable PACPUS_ROOT is well defined in your setup.

The repository containing the tutorials is accessible through the URL in this command:

cd ~
mkdir dev && mkdir pacpus
cd dev/pacpus
svn co https://devel.hds.utc.fr/svn/pacpustutorials

The repository contains several folders:

• template: you will find here some source codes (CMakeLists.txt, .cpp and .h) useful for the exercises.
• exercises: the wording of each tutorial. The wordings are available below too.
• solutions: the solutions of the exercises (coming soon)

Basic Concepts

Tutorial n°1: Creating your first PAPCUS project

The objective of this exercise is to understand the build process of a PACPUS project. The utility 'cmake' is used to create the Makefile of the project, and finally we use the GNU Compiler Collection to build the plugins.

Thanks to the different source codes (.cpp, .h and CMakeLists.txt) in the folder 'template', create a new PACPUS project containing just 1 component. This component may generate a message in the terminal at a user selectable frequency.

Once you have built your plugin, run it in /opt/pacpus/x.y.z/bin folder with the PacpusSensor executable.

Indications:

• You can use QTimer to generate the timer.
• A component can be parametrized in a XML file, it might be useful to change the message display frequency.
• The tree of your project may be something like that:

pacpustutorials
   |
   |--> project_exercises
           |
           |--> plugin_exercise_1
                    |
                    |--> CMakeLists.txt
                    |--> MessageComponent.h
                    |--> MessageComponent.cpp
           |
           |--> build
                    |
                    |--> build_linux.sh
           |
           |--> CMakeLists.txt

Tutorial n°2: Managing the communication of components

Exercise 2.1: communication between components

In this exercise we will develop a new component with one input and one output. The component should add a specific number defined as a parameter to the input value and provide the result as output. Before sending the result on the output it must wait for 1 second. The component will print to the terminal the result of the addition too.

Write the code of this component in a new plugin but use the same pacpus project as the exercise 1. Build and install the plugin in the PACPUS_ROOT/bin folder and execute the plugin with the PacpusSensor application.

Indication:

• Now, the tree of your project may be something like that:

pacpustutorials
   |
   |--> project_exercises
           |
           |--> plugin_exercise_1
                    |
                    |--> CMakeLists.txt
                    |--> MessageComponent.h
                    |--> MessageComponent.cpp
           |
           |--> plugin_exercise_2
                    |
                    |--> CMakeLists.txt
                    |--> AdditionComponent.h
                    |--> AdditionComponent.cpp
           |
           |--> build
                    |
                    |--> build_linux.sh
           |
           |--> CMakeLists.txt

Exercise 2.2: communication of variable size data

Create a new component in the same plugin as the previous one (exercise 2.1). It will have the same functionnality with the difference that it can do an addition on a vector of input values.

Build, install and run this new component.

Indication :

• you can use the QVector class as input/output type.

Exercise 2.3: Threaded component

From the component written in exercise 2.2 create a new component with the same interface. The addition must be done in a separate thread.

Build, install and run this new component.

Indication :

• Your component must inherit from the QThread class.
• Take care of the protection of the data to guarantee a thread safe execution.

Advanced concepts

Soon available...